Regional Update, Influenza and Other Respiratory Viruses. Epidemiological Week 4 (6 February 2026)

Regional Situation: Influenza activity in the Americas continues to decline, with a regional positivity rate of 15.8%. Influenza A(H3N2) continues to predominate among subtype samples in all subregions except the Andean subregion, where Influenza A(H1N1)pdm09 predominates. RSV circulation continues to increase; however, it remains at low positivity levels of 1.5%, driven mainly by increased activity in North America. SARS-CoV-2 positivity remains stable at 5.3%. At the regional level, the circulation of other respiratory viruses (ORV) increased after a sustained decline since early October, with a regional positivity rate of 2.0%. Rhinovirus and parainfluenza remain the most frequently detected ROVs.